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Ch 04: Kinematics in Two Dimensions
Knight Calc - Physics for Scientists and Engineers 5th Edition
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796당신이 사용하는 게 아니라요?교과서 변경
4장, 문제 65a

A typical laboratory centrifuge rotates at 4000 rpm. Test tubes have to be placed into a centrifuge very carefully because of the very large accelerations. What is the acceleration at the end of a test tube that is 10 cm from the axis of rotation?

검증된 단계별 안내
1
Step 1: Convert the rotational speed from revolutions per minute (rpm) to angular velocity in radians per second. Use the formula \( \omega = \frac{2\pi \cdot \text{rpm}}{60} \), where \( \omega \) is the angular velocity.
Step 2: Identify the radius of rotation, which is the distance from the axis of rotation to the end of the test tube. In this case, the radius \( r \) is given as 10 cm. Convert this to meters by dividing by 100, so \( r = 0.1 \, \text{m} \).
Step 3: Use the formula for centripetal acceleration \( a_c = \omega^2 \cdot r \), where \( a_c \) is the centripetal acceleration, \( \omega \) is the angular velocity, and \( r \) is the radius.
Step 4: Substitute the values of \( \omega \) (calculated in Step 1) and \( r \) (converted in Step 2) into the formula \( a_c = \omega^2 \cdot r \).
Step 5: Simplify the expression to find the centripetal acceleration \( a_c \). Ensure the units are consistent (meters per second squared for acceleration).

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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Centripetal Acceleration

Centripetal acceleration is the acceleration directed towards the center of a circular path that an object follows. It is necessary for maintaining circular motion and is calculated using the formula a = v²/r, where v is the tangential velocity and r is the radius of the circular path. In the context of a centrifuge, this acceleration increases with the distance from the axis of rotation.
추천 영상:
가이드 코스
06:48
Intro to Centripetal Forces

Tangential Velocity

Tangential velocity is the linear speed of an object moving along a circular path, measured at a point tangent to the circle. It can be calculated from the rotational speed (in revolutions per minute) and the radius of the circular path. For a centrifuge, the tangential velocity at the end of a test tube can be derived from the rotation speed and the distance from the axis.
추천 영상:
가이드 코스
05:53
Calculating Velocity Components

Rotational Motion

Rotational motion refers to the motion of an object that rotates around an axis. In a centrifuge, the test tubes experience rotational motion, which results in forces acting on the contents due to the rotation. Understanding the principles of rotational motion, including angular velocity and acceleration, is essential for calculating the effects of this motion on the test tubes.
추천 영상:
가이드 코스
07:18
Equations of Rotational Motion
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